The significance of this can certainly be understated at this point, as few applications are built to take advantage of microformats browser-side (adding address cards that are already in your address book to your address book doesn’t make much sense) however, with Greasemonkey and other ideas like GreaseKits making the rounds (okay, so I came up with GreaseKits), we can count this as yet another feather in our cap as more and more large vendors make their web properties more semantically rich, opening up possibilities previously inaccessible given the sheer cost of maintaining one-off scrAPI techniques.

Now when you write a script to parse, augment, enhance or “user-interface-ize” microformatted content, it will work everywhere that microformats show up — not just one site at a time. With Firefox 3 looking to add support for microformats, it’s positive support by folks like Apple that will provide fertile ground for what the next generation of mashable web services looks like.